Manufacture of metal articles



May 28, 1940. c. A. MccuTcHEON 2,202,016

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May 28, 1940. c. A. McCUTCHEON MANUFACTURE OF METAL ARTICLES 4Sheets-Sheet 2 J INVENTOR. 6%;10 WW A TTORNEYS.

Filed lay 23, 1938 May 1940- c. A. M =CUTCHEON 2,202,016

MANUFACTURE OF METAL ARTIGLES In: m 23. 1938 4 Sheets-Sheet s ATTORNEYS.

May 28, 1940. c. A. McCUTCHEON MANUFACTURE OF METAL ARTICLES Filed lay25, 1938 4 Sheets-Sheet 4 INVENTOR} 'ae d- W/c 624% 6%,)? walk/$142211 IATTORNEYS.

Patented May 28, 1940 PATENT OFFWE MANUFACTURE OF METAL ARTICLES ClydeA. McCutcheon, Coraopolis, Pa., assignor to Pittsburgh Forgings Company,a corporation of Delaware Application May 23, 1938, Serial No. 209,403

5 Claims.

My invention relates to the manufacture of metal articles, particularlyto articles that are shaped from bars or straps of steel. The inventionconsists in method.

In Letters Patent of the United States, No. 2,015,194, granted onSeptember 24, 1935, to one Max Ruping, a resilient rail fastener isillustrated and described, and in exemplary way I shall describe thepresent invention as it has been practised in the manufacture of suchrail fastener.

In the accompanying drawings Fig. I is a diagrammatic view in plan ofapparatus in the operation of which the invention is realized. Fig. IIis a fragmentary view in side elevation of a heating furnace and bendingmachine included in the apparatus. Fig. III is a view to larger scale,showing partly in side elevation and partly in vertical section thecooperating dies of a forming press included in the apparatus;'the diesare in open, work-receiving position, and a blank is shown in the matrixof the lower die, ready for the upper die to close upon it. Fig. IV is aview in front elevation of the parts shown in Fig. III, with the blankomitted. Fig. V is a view comparable with Fig. III, showing the upperdie in course of descent upon the lower, and illustrat-' ing the blankpartly formed into the ultimate article. Fig. VI is a view comparablewith Figs. III and V, showing the dies completely closed and the articlecompletely formed. And Fig. VII is a View in side elevation of thefinished article.-

The resilient rail fastener, which in this case is the product of mymethod, is illustrated in Fig. VII of the drawings. It consists in abipartite body that includes a shank portion I and a head portion 2,integrally formed of a medially folded strap of spring steel. The twolimbs of the strap extend from the fold in face-to-face contact, andtogether are shaped into the rail fastener illustrated. The body ofmetal at the fold is externally tapered, as at 3, to provide a bluntpoint at one end of the shank I, and at the opposite end of the shankthe bipartite body of the article extends laterally (reversely curved inits extent) and provides the head 2. The head is in effect a cantileverleaf-spring extending from the shank E. For further details in thematters of structure, use, and advantages of this rail spike, referencemay be made to the Ruping patent, above noted.

I shall now turn to a consideration of the method in which the inventioncenters. In Fig. I the reference numeral 4 is applied to a heatingfurnace in which straps S of steel, cut to proper length, are heated toa temperature at which they may be worked and shaped in the mannerpresently to be described. In this case the steel of which the strapsare formed is a spring steel, including from .90 to 1.05 percent.carbon, and

the straps are heated to a working temperature of 1700 F., more or less.

removed (either automatically or manually) from the furnace, andpositioned one by one upon the table 5 of a bending machine 50.

The table 5 is provided with a medial slot 6,

and upon the face of the table a pair of workshaping blocks 1, I androlls 8, 8 are mounted, one block and one roll on each side of the slot6, as shown in Fig. I. Beneath the table (Fig. II) an endless chain 9 istrained over sprocket wheels [0 and i100, and in known way an electricmotor and driving connections (not shown) are provided for rotating thesprocket-wheels and driving the chain 9 in the direction of the arrowsin Fig. II. The chain carries a plurality of dogs ll that are arrangedat suitably spaced points in the peripheral extent of the chain, and inthe operation of the machine these dogs, moving upward around thesprocket Wheel I00, enter the slot 6 in the table 5 and travel inleft-to-right direction therein. As shown in Fig. II, the distal ends ofthe advancing dogs project above the surface of thetable 5, and aspresently will appear, provide traveling abutments that cooperate withthe blocks 1, I and rolls 8, 8 in shaping the Work.

on the table (Fig. I) and brought to position against the edges la, "laof the blocks; while the strap lies in such position one of thecontinuously traveling dogs II (the first dog to enter the slot 6 whenthe strap has been so positioned) moves into contact with the strap,and, while the opposite ends of the strap bear against stationary edgesTa, la, the advancing dog carries the medial body portion of the strapforward between the two convergent edges lb, "lb' of the blocks. As thecenter of the strap is thus carried inward be tween the blocks l, l, theopposite ends of the strap swing angularly from the edges la, la, andthe body of the strap becomes V-shaped. In the continuous advance of thedogthe strap is carried, with the apex of the V in the lead, from thepass between the blocks l, 1 into and through the pass formed by andbetween the rolls 8, 8, with the consequence and. effect that the legsof the V are brought together, forming the strap into a narrow U-shapedblank B, as shown.

The heated straps'are 5 When the trailing end of the blank B emergesfrom the roll pass, the dog reaches the end of the horizontal coursethrough which the chain 9 travels, and as the chain rounds thesprocketwheel ill in clockwise direction (Fig. II), the dog movesdownward in circular course and is Withdrawn first from the folded endof the blank and then from the slot '5 in the table 5. The blank liesfreely upon the surface of the table.

Before proceeding further, it is to be noted that the gauge-blocks i2,i2 are arranged at unequal intervals on opposite sides of the slot 6 inthe table, to the end that one leg of the U-shaped blank shall beslightly longer than the other, as shown in Fig. I. The advantage ofthis refinement will presently appear.

At the delivery end of the table 5, two forming presses l3, B3 arearranged, and in these presses the U-shaped blanks B are formed into thearticle shown in Fig. VII. Ordinarily, one press only is operated, theother being held in readiness in case of a breakdown. In service theblanks B are removed (either mechanically or manually) from the table 5,and introduced one by one to the active forming press. In a singlestroke of the press, each blank 13 is formed into a finished article(Fig. VII).

Upon leaving the forming dies of the press, the formed articles movedown a slideway H30 to the surface of an endless conveyor i l, and onsuch conveyor are carried into an annealing or quenching furnace l5.Emerging from the annealing furnace, the articles are conveyed through aquenching bath 1%, and from the quenching bath the articles go to theusual draw furnace 59. If, as sometimes will be the case, the drawfurnace is remote from the quenching bath, the articles are collected ina receptacle i! at the delivery end of the bath, and in such receptaclethe articles are carried to and introduced to the remote draw furnace.If, on the other hand, available space permits the draw furnace 58 to belocated adjacent to the discharge end of the quenching bath, thearticles coming from the bath are conveyed immediately into the furnace.

It will be understood that the operation of the press l3 and the speedof the conveyor i 4 may be so regulated that the forged articles aredelivered to quenching furnace 5 at temperature of from 1200 to 13%degrees F. the speeds of advance of the articles through each unit ofthe apparatus may be regulated so that the annealing, quenching, anddrawing of the articles is accomplished in accordance with recognizedgood practice. Further detail in the matter of heat treatment isunnecessary to a full understanding of the invention.

Turning to a consideration of the structure and mode of operation of thedies in the forming presses I3, attention is directed to Figs. III toV1. Each press includes a female die and a male die. The female dieconsists in an anvil block l8 which is integrated with a base 20, andthe male die consists in a block 59, held in assembly with a head 2i, bymeans of a plurality of vertical stemsin this case four stems 22. Thefemale die assembly i8, is rigidly secured upon the bed of the press(not shown), while the male die assembly 59, 2| is carried by thevertically reciprocable cross-head of the press. I do not show the pressstructure proper, for the reason that there are many known makes ofpresses which may be used, and there is no radical departure from commonpractice in the manner in which I assemble the dies in the press.

When the cross-head of the press is at the upper end of its stroke, thedies are separated, as shown in Figs. III and IV; and, alternately, whenthe cross-head is at the lower end of its stroke, the dies arepowerfully closed, as shown in Fig. VI.

Within the upper face of the die block 23 a matrix 23 is formed, andthis matrix is adapted when the press closes to receive a male portion22 carried by the die block i9, and to cooperate with such male dieportion in shaping the folded end of a blank B into the shank portion 1,3 of the rail fastener. (Note Figs. VI and VII.) The matrix 23 iscontinued downward from the upper horizontal face of the die block itbetween two vertical flanges 25 on the side of the die clock, and thebody of the block between these flanges is contoured, providing a matrixportion 23a in the form of the head 2 of the rail fastener. And it willbe noted that the outer edges" of the flanges 25 are parallel with thecontoured Wall of suc'n matrix portion.

In accordance with the invention, I provide means that cooperate withthe matrix portion 23a, while the folded end of a blank B is by the maledie held captive in matrix 23, in forming the bipartite end of the blankinto the c 'ved head of the rail fastener. Advantageously, such meansconsist in a roll 26, arranged between, and trunnioned in, the lowerends of a pair of lever arms 2']. The lever arms 2? are pivoted, on acommon axis 28, to the body of the upper diecarrying block 2|, and atension spring 29 is secured between such block and the upper end ofeach arm 21. The block 2i carries abutments, in this case in the form ofrigid pins 2'58, for preventing the arms 2'! from swingingcounterclockwise from the vertical position in which they appear, onebehind the other, in Fig. HI, but it will be understood that, opposed byspring tension, the arms may swing in unison through a limited range inclockwise direction. On the base 20 of the lower die assembly twovertical cam-bars 30 are rigidly mounted, and on the axle 33 of the roll26 at the lower ends of lcvcr arms 2'! two cam rollers 32 are mountedfor free rotation. In the operation of the press, when the upper dieassembly closes upon the lower, the rollers 32 (moving downward with theupper die assembly) engage and roll upon the inwardly curved edges 3! ofthe cam-bars with the consequence and effect that the descending leverarms 27 are swung clockwise and the roll 28 caused accurately to shapethe bipartite end of a blank B to the contour of the matrix portion 23a.Before describing the operation in greater rictail, there is anotherfeature of construction that should be described.

As already mentioned, the upper die block 99 is assembled with thesupporting block 2 i, by means of four stems 22. These stems consist. inthis case, in bolts whose threaded ends are rigidly sccured in the bodyof the block 2%; the four bolts xtend in parallelism downward from thsupporting block 2| and carry heads [52a at their lower ends, andbetween the heads 22a and the body of block 2i, the die block E9 isvertically movable on the shanks of the bolts. A helical. compressionspring 36 is mounted on the shank of each bolt or stem 22. These springsare effective between the blocks 25 and i9, and tend to maintain theblock H5 in a position spaced from the bottom of block 2|, with thebottom of the block 19 bearing against the heads 6f the bolts 22. (NoteFig. III.) And it is'to be noted that the bodies of the blocks l9 and 2iare recessed, as at 35, to receive the opposite ends of the springs 34.By virtue of such structure, the block 2i may, as presently will appear,be closed tightly upon the block 19, with the springs 34 compressed andnested entirely within the pockets 35.

In the operation of the press, a heated blank B is removed from thetable 5 (Fig. I), and, while the continuously reciprocated upper dieassembly is at the top of its stroke, the blank is positioned in thematrix 23 of the lower die block. It is important to note that theU-shaped blank is placed in the matrix, with the longer leg of the Uabove the shorter, and in order to facilitate the accurate positioningof the blank in the matrix, I provide a fixed, though adjustable, stop36. (Conveniently, the stop 36 is carried by the cam-bars 3%), asshown.) The blank B is positioned in the die block it with the longerleg of the U abutting against the stop 36. (Note Fig. III.) Presently,the continuously reciprocated upper die assembly descends, and in thecourse of such positive movement the following operations are effected:

1. The male die portion 24 of the die block it enters the matrix 23 andengages the folded end of the blank B. The downwardly moving die blocki9 is arrested, with the folded end of the blank securely clamped, underthe tension of springs 33, between the die blocks l8 and I9..

2. While the two limbs at the folded end of the blank are thus heldagainst longitudinal displacement in the matrix 23, the spring-resisteddescent of the block 2i and lever arms 21 continues unabated; theinterval between the blocks l9 and 2! decreases, the rollers 32 at thelower ends of the lever arms 2?, thus carried downward, make contactwith the upper ends of the vertical cam-rails 3Q; the compression ofsprings 34 increases; and the pressure on the clamped end of the blankis correspondingly increased,

3. The roll 28, carried downward by the descending lever arms 21 movesinto contact with the paired limbs of the blank extending from theclosed dies. As the movement of the descending parts continues withoutinterruption, the otherwise free limbs of the blank are by the rollpressed downward and rolled, from a medial point outward, limb againstlimb, into the crookshaped matrix portion 23a. (Note Fig. V.) The camedges 3! are so contoured that, as the rollers 32 move downward incontact therewith, the paired lever arms 2?, holding at first to astraight vertical course, swing clockwise and move the descending roll26 through such path that the bipartite end of the blank is formed tothe exact curvature of the matrix portion 23a. The desired crook-shapedhead is thus formed in the article. (Note Fig. IV.)

4. As the roll 26 approaches the end of its blank-forming sweep, thesprings 34 are completely compressed within the pockets 35 and thedescending block 2! closes upon the die block l9. While the bipartiteend of the formed crook is by the roll 25 secured upon the contouredsurface of the die block 58, the supporting block 2! abuts upon the dieblock is and presses it downward with great pressure. That is to say,the die block 89 is forced downward from the position shown in Fig. V,in which it primarily serves to clamp the folded end of the blank uponthe block l8, to the position shown in Fig. VI, in which the male dieportion 24 cooperates with the matrix 23 in tightly closing the foldedend of the blank and pressing it to its ultimate shape. that the dieportion 24 and matrix 23 are so particularly fashioned (at 24b and 231))that the desired slight taper 3 is provided at the pointed end of theshank.

5. Simultaneously with such powerful closing of the die block l9 uponthe block l8, the crookshaped head of the formed article is engaged by aportion of the block 2i. That is, a rigid die portion 2| a depends fromthe body of the block 2!, and the lower end of this portion Zia isshaped to the curvature of the formed article, in the region between theshank portion I and the head portion 2. As the die block l9 enters itsultimate shank-forming position (Fig. VI), the

die portion Zia closes tightly upon the shaped blank, as shown, with theeffect that not only is relative movement between the two limbs of theformed article prevented, but a set is given to the metal in the regionof greatest curvature.

The advantage of forming one leg of the U shaped blank longer than theother will now be manifest. Comparing Figs. III and VI, it will beunderstood that, while the folded end of the blank is held againstlongitudinal displacement and the roller 25 is shaping the bipartite endof the blank against the contoured die block, the outer ends of the twolimbs of the blank are free for relative longitudinal movement. Thus,dur-. ing the rolling of the bipartite end of the blank against theconvex face of the die block it, relative movement between the outerends of the limbs is effected. The greater length of the upper limb ofthe U makes compensation for the radial difference in curvature betweenthe inner and outer limbs of the blank, so that in the finished articlethe outer ends of the two limbs lie flush, or substantially so, as shownin Figs. VI and VII. In refinement of the apparatus described, I providemeans for laterally aligning the two limbs in the shank portion of theformed article, it being noted that the two flanges 25, 25 on the sideof block l8 serve to insure alignment of the limbs in the crook-shapedhead portion. Such means consist in a die plate 38 (Fig. IV) arranged ina slideway 39 in the body of the lower die block H3. The upper die blocki9 carries a cam block 40 which, when die block I 9 is powerfully closedupon block 18, moves downward upon an inclined face 38a on the outeredge of die plate 38, and effects the movement of the die plate inward,pressing its inner edge forcefully against the folded body of metalwithin the matrix 23. In such manner the two limbs of the article aredie-pressed into precise alignment.

In still further refinement of the apparatus described, I provide meansfor dislodging the formed article from the matrix in die block 18.Specifically, I provide an orifice 6| in the wall of the matrix,preferably in the contoured floor of the matrix and at the point wherethe convexity of the contour is greatest. (Note Figs. III to VI.) Fluidunder pressure is supplied to this orifice, and preferably compressedair is the fluid used. In this case a tank 62 of compressed air isconnected to the orifice, by means of a lead 63 and a passage 64 formedin the body of the die block. Advantageously, if not essentially,communication between the tank and the orifice remains open, and so longas the orifice BI is uncovered a jet of air plays into the openatmosphere.

When in service the upper die assembly of the machine descends andpresses thebipartite end It will be noted of a blank into the matrixportion 23a, the orifice SE is closed by the body of the metal beingworked. The flow of air from the orifice is thus interrupted, but itwili be understood that air at supply pressure is eifective upon theinner surface of the crook-shaped head of the formed article. When indue course the upper die assembly rises, this air pressure is eiiectiveto dislodge the formed article from the die l8, and the blast of airthus released blows the article longitudinally away from the die anddirects it to the slideway 133 (Fig I), whence the article moves undergravity to the conveyor 54. It may additionally be men tioned that thestreaming air, impinging upon and deflected by the body of the articleleaving the die, serves to cleanse the matrix of scale.

In the operation of the apparatus above described the method of thisinvention is practised, and it will be understood that the invention isnot limited to the manufacture of rail fasteners of the sort hereindescribed.

In the foregoing specification the dies have been described as theyoperate in a vertically reciprocable press, but it will be understoodthat they may be embodied in a horizontally reciprocated press orbulldozer. And it goes without saying that other departures from thedescription may be made within the terms and intent of the appendedclahns. And as an example of a variation contemplated, I mention thatthe limbs of the U-shaped blanks need not be spaced apart, as described;that is to say, the limbs may be tightly closed in surface-to-surfacecontact be fore the blanks are introduced to the dies of the formingpress.

I claim as my invention:

1. herein described method which consists in folding a strap of steelinto a U-shaped blank, clamping the blank at its folded end upon acontoured die block and rolling a crook in the opposite otherwise freeend of the blank against the contoured face of the block, and, while theformed crook is secured between the rolling instrumentality and the dieblock, pressing the two limbs of the blank extending between the crookand the folded end into the form of a shank.

2. The herein described method which includes folding a strap of steelinto a U-shaped blank, clamping the blank at its folded end upon acontoured die block and forming the opposite otherwise free end of theblank against the con toured face of the block, and, while the so formedend continues secured beneath the forming instrumentality and the dieblock, die-shaping the folded end of the blank.

3. The herein described method which includes folding a strap of steelinto a U-shaped blank, with one limb of the U of greater length than theother, clamping the blank at its folded end upon a contoured die blockand forming the opposite otherwise free end of the blank, limb againstlimb, against the contoured face of the block and with the shorter limbof the U positioned between the face of the block and the longer limb,and, while the so formed bipartite end of the blank is secured betweenthe forming instrunientality and the die block, die-shaping the foldedend of the blank.

4. The herein described method which includes forming metal into aU-shaped blank, with one leg of the U longer than the other, and, whileadmitting of relative longitudinal movement between the distal endportions of said legs, shaping the bipartite end of the blank into acrook and bringing the ends of the legs into juxtaposition at the tip ofthe crook, and, while securing the constituent portions of suchbipartite crool: against relative movement, pressing the portions of thelegs between said crook and the bend in the U into the form of a shank.

5. The herein described method which consists CLYDE A. MCCUTCHEON.

